Stability of surface reflectance scaling properties explored by using SPOT-VGT data

VGT reflectance data acquired in four spectral bands (B0, B2, B3 and MIR) from 1998 to 2005 by SPOT-VGT were investigated. VGT data are characterized by global coverage and consistent image quality and are particularly suitable for time series investigations. The analysis was carried out for a test area located in the island of Sardinia. The study area is covered by shrubs, mainly Mediterranean maquis, which is the typical vegetation cover of the Mediterranean basin. Deviations from uniform power-law scaling were quantified by using detrended fluctuation analysis (DFA). The results indicate a larger non-uniform scaling behaviour in the B0 channel. This can be applied to understanding radiation interactions at the surface as required for advancing weather forecasting, climate studies and environmental monitoring.